1. Field of the Invention
The invention pertains to a device for lifting a hatch which can pivot around a pivot axis, especially a hatch of a motor vehicle, by means of a piston-cylinder unit, where the piston-cylinder unit has a closed cylinder filled with a pressurized fluid, the interior of the cylinder being divided by a piston into a first and a second working chamber, the piston being free to move axially back and forth in the cylinder. A piston rod is being attached to one side of the piston, the rod passing through the second working chamber and being guided to the outside through a seal at the end of the cylinder and then hinged to the hatch or a stationary component, whereas the other end of the cylinder is hinged to the stationary component or to the hatch, where a through-opening, which can be opened and/or closed, leading from the first working chamber to the second working chamber, is provided in the piston.
2. Description of the Related Art
In devices of this type it is known that an actuating plunger extending through the piston rod to the outside can be used to open and to close the through-opening manually.
This always means, however, that the actuating person must be present in the area of the hatch and must, in each individual case, decide to actuate the device and then actuate it.